Despite their different etiologies and clinical as well as pathological manifestations, most neurodegenerative disorders are characterized neuropathologically by aggregates of abnormal filamentous proteins that progressively accumulate in selectively vulnerable regions of the central nervous system (CMS). Different disease proteins form distinct CNS lesions that are diagnostic hallmarks of specific neurodegenerative disorders. While the clinical variants of frontotemporal lobar degeneration. (FTLD) or frontotemporal dementia (FTD) syndromes are relatively well defined, characterization of their underlying neuropathology is incomplete. Indeed, clinically defined FTLD syndromes may be associated with several different neuropathological substrates, including Alzheimer's disease (AD) plaques and tangles, but the relationship of clinical FTLD syndromes to specific neuropathologies is incompletely understood. Thus, postmortem examination of CNS tissues from FTLD patients is essential for developing accurate and reliable clinicopathological FTLD diagnostic criteria, as well as to provide highly characterized CNS tissue samples for research. The growing cohort of FTLD patients followed in Core A of this Program Project Grant (PPG) and the increasing number of postmortem brains/spinal cords obtained from these patients provide a compelling rationale for the Neuropathology Core (Core B) in this PPG. Thus, the Aims of Core B support the goals of this PPG by providing diagnostic neuropathology, CNS tissue banking, database tracking of samples and neuropathology data on all FTLD subjects followed in Core A of this PPG who consent to autopsy as well as by providing advice to PPG investigators on the use of neuropathology data or samples from this Core in their research.